Winding for rotating fields.



HBRTZ. WINDING FOR ROTATING FIELDS.-

APPLICATION FILED m. 2, 1906. H

Patented Dec.29 ,1908.

BEETS-SHEET 1.'

H. HERTZ. WINDING FOR ROTATING FIELDS.

AIFPLIOATION FILED 141m, 1906.

' Patented Dec. 29, 1908.

2 SHEETS-SHEET 2.

, Ewe/150w; Ij'almar fiiif .core, the disks being insulated from U *ITEDSTATES PATENT OFFICE."

HJALMAR HERTZ, OF CHICAGO, ILLINOIS, ASSIGNOR TO WESTERN ELECTRICCOMPANY, OF

CHICAGO, ILLINOIS, A CO RPORAT ION OF ILLINOIS.

WINDING FOR ROTATING FIELDS.

Specification of Letters Patent.

Patented Dec. 29, 1908 To all whom it may concern:

Be it known that I, HJALMAR HERTZ, a citlzen' of the United States,residing at Ohicago, in the county of Cook and State of Illi- I nois,have invented a certain new and useful I Improvement in 'V'Yindings forRotating Fields, of which the following is a full, clean! concise, andexact description. My invention relates to a rotor fordyname-electricmachines, and is ap licable more particularly nets of alternatingcurrent generators of'the high speed type. In the case of generators ofthis type, which are intended to be directdriven by steam turbines, thevery high speed of rotation imposes strict limits in the size of therotor, and further. makes it essential to have the rotor'as nearlysymmetrical and mechanically balanced withrespect to its axis ofrotation as possible. The. enormous centrifugal force which is exertedgives rise to the. further requirement that the winding of the rotorshall be composed of parts which are comparatively large andsubstantial, so as to permit of their-being efl'ectively secured inplace. For these reasons it I is convenient to construct a rotor'with aniron core and heavy bar conductors embed-' (led in longitudinal slots inthe eriphery of the core, the end connections etween theseveralconductors being formed by disks assembled upon the shaft at the ends ofthat eac other and from all the conductors except those to which theyare immediately connected. Such a construction is described in anapplication of Charles H. Smoot, Serial No. 294,044 filed January 2,1906. The object of the present invention is to provide a scheme forwinding a'rotor having the mechanical construction above referred .fieldmagnet for a to, in such manner that the parts may be easily assembled,that the terminal conductors of the winding may be led out atopposite'ends of the rotor, and that thecompleted structure shall besymmetrical and mechanically balanced with respect to its axis ofrotation.

' I will describe my improved scheme of winding in accordance with theaccompanying drawing, in which- Figure 1 is a perspective view of arotating ynamo electric generator of the type to which my improvedscheme of winding is especially int-ended to be ap to the rotating fie dmagplied; Fig. 2 is a cross sectional view thereof; Fig. 3 is a diagramillustratingthe scheme of winding, the rotor indicated being consideredas developed into a plane Fig. 4 is a simplified diagram illustratingthe theory of winding, considering only a few turns, and only oneconductor in each slot of the core.

As shown in Figs. 1 and 2, the armature consists of acore a composed oflaminated sheet. iron disks assembled upon a shaft 5, said core having aseries of longitudinal holes or slots near its periphery, in which theconductor bars 0 of the winding are intended to be embedded. In the formof rotor shown there are three conductors, 0', c 0 in each slot, saidconductors being radially superposed. The several conductors are all connected in series by connector disks d,-d, at the ends of the rotor, saidconductors and disks being suitably insulated, and forming a serieswinding to on diametrically opposite sides of the rotor.

l The rotary field magnet shown is of the bipolar type, but itwill beevident that y invention is capable of application tomagnets'of themultipolar type.

In accordance with my invention, the winding is so arranged that theterminals thereof will be brought out at opposite ends of the rotor, sothat end clamping disks may be applied upon which contact brushes maybear to convey current to and from the winding. To obtain this result,while at the same time maintaining a mechanically balanced structure, Ihave devised the scheme of winding shown diagrammatically in Figs. 3 and4. The scheme can perhaps be best understood by considering the windingas made up of two sets of convolutions united produce magnetic polesatthe middle part of the rotor, and proceeding outwardly in oppositedirections until the terminal disks at the opposite ends of the rotorare reached, the winding, however, being unidirectional with respecttothe flow of current from one, terminal to the' other. -In assemblingthe winding, the conductors and connector disks forming the middleportion ofv the winding are I held magnet core, and. t e winding. isthen built up progressively from the middle portion toward each endthereof, thus naturally bringing the terminal conductors and end plateson the outside of themagnet Another way of considering the winding-4sthat laced first on the 2 scenes it starts with one end disk andgradually It will further be noted that the scheme of wlnds nward untilthe core is'reached, after winding shown in Fig. 4, in order to bringwhich 1t continues to wind the same di1ecthe terminals at opposite endsof the rotor, tron from the field core outward until it terinvolves agreater number of longitudinal '5 minates m a disk at the opposite endof the conductors or lengths at one side of the axis 70 rotor from thestartingpomt, having made than on the. other; and in the actual conthenumber of turns and groups of turns'both' struction of a rotor accordingto this plan, ways. The inward and outward going preferably rovide adummy conductor on pups of turns are combined alternately that side theaxis of the winding which with respect to the circumference of theotherwise would have the fewest number of rotor. lengths of the actualwinding, this dummy Referring to Fig. 4, the scheme of winding conductortherefore serving to balance the will be readilyunderstood. It will beseen weight of the conductors on the opposite that the windingiscomposed of two sets of sides of the axisof thewinding. T e"-dia- 15eonvolutions, one set being ind cated in grammatic windmg' illustratedin Fig. 4 lines, and the other set being indicated shows the arrangementif there were only dotted lines, the two sets being united at theone'conductorineach slot of the core. Where middle portionof thewinding. 'l'he'axis of there are several turns of the winding, so to thewinding is indicated by the dotted lines speak, in each slot, the samegeneral schemev 9 *x-t. It will be understood that in a bipolar will befollowed, but there will naturally :be

machine this dotted line will correspond with somewhat more complicationin the relative the axis of rotation of the rotor, but thisarrangement-of the connector disks. statement would not of course betrue-with Referrmgto Fig. 3, the diagramillustrates respect. to amultipolar magnet. Still rea windin inwhich there are three conductors25 ferring ta Fig. 4, he horizontal lines c-in the in eachslot of thecore, these conductors be a0 diagram of the wlndm indicate conductor ingradially superposed n the diagrarnaihe -b'ars, while the vertica lines41, (1, indicate line :'c-c indicates the axis of the winding; endconnectors for said conductor bars, such, the horizontal lines indicatinthe longitudifor' example, as the disks illustrated at the nalconductors'embedded in s ots inithe core, 30 ends of the rotor shown inB ig. 1. Considerand the vertical lines indicating the connector ing newthe innermo'st connector disks (1, d, disks at the ends of the rotor.There bein A of thetwo groups at the ends of the rotor, threeconductorsin each slot, the horizonta these are connected by a conductorbar lines are indicated in groups of three conwhichfforms the middlelength, so to s eak, ductors each, and as these conductors in the v 35of the winding, and the two nnermost isks, actual machine are radiallysuperposed, the

' co ecting d and d, and indicated in full and dotted also ma espossible a d'andd' may be taken as the starting points relativearrangement of these conductors is for thesets of .convolutions shownrespecindicated bytheir position with respect to tivelyin full lines anddotted lines. It Wlll each other that oneof any roup of three benotedthat these sets of convolutions proconductors which is nearest t eaxis n 40 ceedoutwardly opposite directions, an the diagram indicatesthe radial innermost finally terminate in outermost disks d andconductor of the slot. Similarly, that oneof v ((ZPat the ends of therotor. I Clamping any gro pv of three conductors which is fardisks'orplates,'e, e, are assembled upon the thest from the axisline a;'-windicates the Y shaft of the rotor outside the terminal disksconductorwhich is radially outermost in the as d and (d), andmake-contact respectively slot. w I i V with said terminal disks, saidend plates, 0 It will be seen that preferablythe radially an e",havingxgurfaces, f, f, upon which. innermost conductor in each slot isthe lon s s, g, g, {are adapted to'bear est, that is,'it is extended toa connector dis "to convey current to and from the winding. which liesoutsidetheconnectordisks of the I, I 50 Referring to Fi i, it will beseen that as uppermostconductors This is forthe pur the sets of convoutions, beginning at disks pose of reater conven enceiin assembly, andstronger, construction lines, respectivel proceed outwardly, each of.the rotor to withstandcentrifugal'for'ce. .longitudinalcon actor ofeachsetissxtende Such-"a relative arrangement of the con-' 55 to aconnector disk which lies outside the i-nductors in the slot isdescribed in the apphca tervening. connector disk *belongmg to a tionofCharles H. Smo'ot, before referred to. neighboring conductor of the oposite set. Considerm thewinding shown diagram'- It. will be, furthernoted that suc connecmatically n 1g. 3, therefore, it willbe seen tionsto the connectordisks are made alterthatit is composed of two sets ofconvolu- -60 jnatel'y on different sides' of the-axis of wmdtionsbeginning withaconductorum the mg and that when'a dotted conductor'isexinnermost'connector d and d 'tat thetended below the axis :r-x to' itsconnector ends of the rotor, and proceeding outwardly disk,thecorresp'onding conductor showniin in opposite d1rect ons, -be1ngfinallytermifulllines is extended above the axis a;x to nated 1n theouter orrend disks ((1 and d) 5 its disk, and vice 've'rsa.

. at the opposite ends of there r. Each set 4 the neighboring ,sulatedfrom su which it passes.

' claim of the winding being assembled ductor uniting the ofconvolutions has its conductors or arranged in groups of three, therebeing one i group for each slot in the core, and these I groupsbelonging-to the two different sets of convolutions, are dispos turns 1ed in alternations upon the circumference of the core.

It will further be seen that each eonvolutions ends in a conductorextended to a connector which is disk lying outside group of conductorsof the other set, said terminal conductor being inch intervening disksthrough It will further be seen that such extensions from the successivegroups of convolutions are located alternately on opl l I I I I positesides of the axis of the winding so that i said winding is madesymmetrical, and is l mechanically balanced. I Like the simplifiedwinding shown in'Fig. 4, there will .necessarilybe one more horizontalconductor on one side of the axis of the winding than on the other, dueto'the fact that the terminals are brought out atopposite ends of therotor, winding shown in Fig. 3, I also provide a I dummy conductor h onthat side of the axis which has the fewer number of lengths of theactual Winding. Having thus described my invention, I

and in the form of] 1. A rotor for dynamo electric machines consistingof a core, conductors extending longitudinally of the core and endconnectors uniting said conductors in series to form a Winding, saidwinding starting at the outer one of the connectors at one end of thecore and proceeding inward to the inner connec- I tors nearest the core}and then continuing i outward by way of connectors which are l disposedintermediate the connectors of the first portion, finally terminating inthe outer I connector at the opposite end ,of the armature from thestarting point.

2. A rotor for dynamo electric machines comprising a core, longitudinalconductors i and end-connector disks uniting said 0011- I duetors inseries to form a winding, the conductors and disks forming the middleportion first upon the body of the core and the winding built upprogressively from such 'middle portion to- Ward each end thereof,whereby the terminals of the winding are led out .at opposite ends ofthe rotor, while the entire structure is symmetrical and mechanicallybalanced.

3. A rotor for dynamo electric machines, comprising a core, a group oftransverse insulated disks at the ends of said core, a con,-

innermost disks of the two groups, and additional similar conductorsconnected inseries with said first mentioned tions and terminatingrespectively in the outermost disks of the two groups.

a. A rotor for dynamo electric machines, comprising acore, a group oftransverse insulated disks at the ends of said core, a conductor unitingthe innermost disks of the two groups, and additional similar conductorsconnected in series with said first mentioned conductor by the outerdisks to form a unidirectional winding for said core in the two sets ofconvolutions, beginning with said two innermost disks, proceeding inopposite directions and terminating respectively in the outermost disksof the two groups,'and a dummy conductor to equalize the weight ofconductors on opposite sides of the axis of the winding.

5. A rotor for dynamo electric machines comprising a core and aunidirectional winding comprising longitudinal conductors and endconnections, said winding consisting of two sets of convolutions whichbegin with the innermost end connections and proceed 6. A rotor fordynamo electric machines comprising a core, conductors extendinglongi"tudinally thereof, and insulated connector disks at the ends of saidcore uniting said conductors to form a unidirectional winding, saidwinding being composed of two sets of con volutions beginning with aconductor uniting the innermost connector disks of the groirps at therespective ends of said core, proceeding outwardly in oppositedirections and terminating in the outer or end disks of the respectivegroups, the two sets of convolutions having their conductors arranged ingroups which are disposed alteriiately in succession around thecircumference of the core.

7. A rotor for dynamo electric machinescomprising a core, conductorsextending longitudinally thereof, and insulated conhector disks at theends of said core uniting said conductor s to form a unidirectionalwinding, said winding being composed of two sets .of (onvolutionsbeginning with a conductor uniting the innermost connector disks of thegroups .at the respective ends of said core, proceedingoutwardly inopposite directions "and terminating in the outer or end disks oftherespective groups, the two sets of convolutions having theirconductors arranged in groups which are disposed alternately insuccession around the circumference of the core, each group ofconvolu'tions ending I 111 a conductor which is extended. to aconv s pscore, each group of convolutions ending in 8,

conductor which is'entended to a, disk lying outside the interveningdisks of the neighboring group of conductors of the other set, saidterminal conductor being insulated from such intervening disksthrough.which it passes, such-extensions fromthe successive groups ofconvolutions being located on 0pcomprising a core, conductors extendinglongitudinally thereof, and insulated connector disks at the ends ofsaid core uniting said conductors to form aunidire'ctional winding, saidwinding being composed of two sets of convolutions beginning with aconductor connectoruniting the innermost connector disks of the 1ositesides of the axis of the winding, wheregroups at the respectiveends of said core, I y'said'winding i'ssyminetrical andmechanproceedingou fiwardly' in opposite directions ically balanced, J

and terminatingin the outer or e d disksof In witness whereof, Ihereunto subscribe the respechve groups, the two ts of conmynmn'ethis 29day of Dec. A. D., 1905. volutions having their cofiductors'srranged tHJALMARHERTZ,

which are disposed alternately-1n. r Witnesses: I r v v H, Moons,

" G.'E. Font.

succession around the circumferenceof the

